Magnetic speedometer



Juy W, R923. EALSLZS J. PATRICK r MAGNETIC SPEEDOMETER Filed Dec. l,1921 anne-nto@ 'Patented July l0, i9,

'arene JOSHUA PATRICK, OF DETRIT, MICHIGAN.

.maar

MAGNETIC SPEEDOMETER.

Application led December To all lwhom it may concern.'

Be it known that I, JOSHUA PATRICK, a citizen of the United States, anda resident of Detroit,"county of Wayne, and State of Michigan, haveinvented certain new and useful Improvements in Magnetic Speedometers,of which the following is a full, clear,

concise, and exact description, such as will enable others skilled inthe art to which vthe invention relates to make and use the same,reference being made `therein to the accompanying drawings, which form apart of this specification.

My invention relates to speed indicating' devices of speedometers usedin connection with motor driven vehiclesI to lindicate the speed atwhich the same are driven, andparticularly to speedometers of themagnetic type wherein an angularly rotatable speed cup is movedthroughout Various angles vby the action of eddy current induced thereinby a rotating armature, the poles of which move adjacent a magnet withinthe field of which the speed cup or a ortion thereof lies. The principalobject o my invention is to provide a speedometervof the class or typeabove referred to wherein all the parts thereof may be assembled upon afoundation or supporting platewhich closes an opening in the case of theinstrument; and then introduced into or removed from the case as asingle unitaryl structure, all the elements of the instrument beingsupported solely and l.

'1s secured to the front plate of the instru- 90 entirely by and fromsaid front plate, and independently of the casing of the instrument.

A further object of my invention is to provide an improved speedometerof the type in question in which the shaft whereby the same is drivenfrom the vehicle is connected with the rear wall of the instrumentcasing and extends substantially at right angles therefrom; said drivingshaft. being operatively connected witli the armature of the instrument,through a sliding joint; and the armature and a l the other operatingparts of the instrument being supported from a` front plate which isremovable from the casing, so thatfsaid plate andthe parts carriedthereby may be removed from the casing without disconnecting the drivingshaft therefrom.

With the above and other objects of' invention in View, as willhereinafter and at length more fully appear, myinvention consists in theimproved magnetic speedometer l, 1921. Serial No. 519,211.

illustrated in the accompanying drawing and hereinafter described andclaimed; and 1n such variations and modiications thereof, within thescope of the concluding claims, as will be` obvious to those skilledinthe art to which my invention relates.

In the drawing accompanying and forming a part of this specification,and wherein the preferred embodiment of my invention is illustrated: Y l

Figure l is a view showing my improved A speedometer in elevation and asseen kfrom -the front thereof, portions of the plate which supports thevarious operating parts of the instrument being broken away in order tobetter illustrate parts otherwise hidden by the supporting plate.

Figure 2 is a view showing a section upon a vertical plane indicatedapproximately by the line 2-2, Figures l and 3, of the principaloperating parts of the instrument.

' Figure 3 is a view showing the frontv supporting plate' and variouselements of the. instrument carried thereby, the casing of theinstrument being omitted and the view showing a section upon a planeindicated approximately by the line 3-3, Figure 2, looking toward theleft. v 4

Figure 4 is a fragmentary sectional view 85 taken upon'a plane mdicatedapproximately by the line 1 -4, Figure 3, showing the manner in whichthe support for the rear bearing member for supporting the armaturement. lReferring now to the drawing, the reference numeral 5 designatesthe main casing of the instrument which may be made from pressed metal,as a die-casting, or otherwise 9e and-which casing is hollow andcup-shaped in form, and open along one side or` end thereof;A saidopening being surrounded by an outwardly extending flange 6 which isprovided with holes through which the loo screws pass whereby theinstrument as a whole is secured in place in an opening provided in thedash or instrument board. rl`he casing shown is made from comparativelythi'n metalA and is provided with a hollow 105 bushing 7 secured uponthe inner surface of the rear wall thereof and extending -through anopeningV therein, andA to which bushing the non-rotating external casing8 of the flexible driving shaft through my which the instrument isdriven is secured as by means of a suitable gland nut 9 to therebyconnect the driving shaft and housing to the casing; The plane of the oening of the casing is substantiall y-paralle f with the bottom or rearwall t ereof and is closed by a main foundation plate or cover whichserves as a support for-all theoperating parts of the instrument, thesame being shown as provided With a peripherally extending flange `11which fits closely within 4the open side or end ofthe casing as bestshown in Figure 2 lof the drawing. rll`his 'supporting late 1s commonlymade from die-cast meta altho the method ofits formation is immaterial;and the same isprovided with an opening 12 through which the speedindicating member or speed cup ofl the instrument may be seen andreadpand with other openings 13 and 14 I through whichthe readings ofthe trip andI total odometer wheels usuall 'l present in speedometersmay be read; an also with an opening 15 opposite -the axis of rotationof therotating parts of the instrument and, across which a bearingsupporting bar`16 extends, to thereby provide a support for the outer:jewel bearing of the speed cup shaft of the instrument. y

The reference numeral 18 4designates the magnet of the instrument whichis secured to the supporting plate .10 by agscrew 20 extending betweenthe poles thereof andI through a clip 21, and a second clip 22 whichengages the magnet near the middle portidnthereof, themagnet as a wholepreferably lying within a. recess 23 provided for it in the foundationlplate in order `that it may be more fixedly. held in position; and

' .said foundation'plate is preferably provided with aprojecting lug 24which lies between the poles of the magnet and maintainsv them theproper distance apart. While I have illustrated the magnet as ofhorse-shoe form i it will be appreciated that a magnetic element ofother form may be used such, for example, as two or more magnetsarranged with their poles adjacent one another.

Located within the casing 5 and secured to the supporting plate 10 is asupporting member 24 which is substantiallyl cup-shaped Ain form andmade preferably from thin non- /inagnetic sheet metal having highvelectrical resistance to prevent the formation of eddy currents, theouter' endv of-said member being secured to the said plate as by meansof screws 25' thel heads .of which overlie the peripheral edge of anoutwardlyextendihg n' flange 26 of said memberiandy said flange beingpreferably lturned towardthe plate at its free edge, as indicated at27,in order that the flange may be properly spaced away from the ad]acentinner-wall of the plate. 'I(l l1e,supr`aortihg plate is preferablyprovided -wlth arc-shaped ledges 28 with which the outwardly turnedportion 27 of the'ange 26 engages, as best shown in Figures Iand' vtion,

resinas 4, to ing member as a `whole within the casing ment.

The supporting member 2x4 which` it will be appreciated is thussupported solely and entirely by and from the frontsupporting plate 10is provided withl a long bearing 29 extending from the inner unsupportedend thereof toward and preferably into the hollow sleeve 7, said bearinghaving an inner annular projecting flange 30 which sur-- rounds a'central .opening provided in the thereby properly position thesupportand relative to the plate 10 of the instru` supporting member.-The bearing is pro- Y videdpwith an internally threaded passageV intowhich a threaded stud 31 of a jewel supporting' member- 32 extends, asbest shown in igure 2, the bearing being thus supported from thesupporting member by the clamping action of the member'32 the peripheryof which lies opposite the flange 30, and serves to clamp the edge ofthe supv porting member 24 surrounding the opening therein between thesaid jewel bearing supporting member and said collar. The supportingmember 24 and the bearing'29 are' functionally a single structure, andmay obviously be made integral if desired.

It will therefore be appreciated that the bearing 29 'is supportedentirely from `the main supporting plate or cover 10 of the instrumentthrough `and by means of the supporting member 24 and extendssubstantially at right angles to the said plate; the said bearing andsupporting member beingsecured to the plate by the screws 25, as

above explained, and the bearing being driving shaft into a similarrecess in the.

sleeve, or in accordance lwith other schemes suitable for providing adriving connection which will be positive as regards rotary mobutnon-positive as regards relative longitudinal movement of the parts, sothat the driving shaft may be removed from 'the casing without injury tothe interior mechanism of the instrument as is ,usual in speedometerdrives.

f The sleeve 33 is threaded 'at its inner end as shown at 34 and thereference numeral 35 designatesthe rotating armature-fof the ment whichis screwed onto the memesvv threaded portion 34 Aand againstja collar 36I provided upon the sleeve.' The armature is v This cylindrical portionof the armature 35 is slotted 'to provide a plurality of separate anddistinct poles 38. The armature is made of iron or other magnetic metal;and the poles thereof which move close to the magnet and speed cup serveto` vary the magnetic flux flowing between the poles of the magnet andinduce eddy currents yin the speed cup of the instrument, in accordancewithv the general mode Lof operation of magn etic speedometers of theclass to which my invention-relates.` l

The reference numeral `39 designates t-he angularly movable speed-cup ofmy improved Iragnetic speedometer', the same having a substantiallycylindrical portion 40 lwhich. lies between the magnet 18 and the polesof the armature so that eddy currents will be induced therein as thearmature is rotated; said speed cup having an outward- -ly extendingflange 41 which moves adjacent the inner wall of the supporting plate 10and across the opening 12 therein, and has figures upon it to indicatethe speed at which 'the vehicle with which the speedometer isk used istravelling, as is usual in such devices.`

'This speed cup is supported by a pivot 42 the inner end of which issupported in a jewel bearing carried by the jewel bearing supportingmember 32, and the outer end of which is supported'in a jewel' carriedby a screw 43 which is in threaded engagement with the cross-bar 16 sothat the bearings for the speed cup may be properly adjusted, said screwbeing locked in position after the speed cup is properly adjusted by alock nut 44. A hair spring 45 is operatively connected' at its inner endwith the pivot 42 and at its outer end with a finger 46 which isadjustably held between the lock nut 44 and the cross bar 16, thepurpose of the spring being to oppose the vrotation thereof and returnthe speedcup to a zero reading and hold it in that position when thearmature is stationary, as is usual in magnetic speedometers.

The armature sleeve 33 is provided with a worm 47 from which theodometer mechanism, indicated conventionally at 48, with which suchinstruments are commonly provided is driven, no specific odometermechanism however being illustrated as the invention to which thispresent application relates is not concerned with the odometer featuresof the instrument; and the said sleeve is held in place upon the bearing29 by a screw 49 in threaded vengagement with the passage above referredto inthe said bearing member.

also as the odometer elements, may be assembled outside the casing andthen introduced into and removed therefrom as a single unitarystructure.

My invention therefore provides a speedometer in which the parts may bemore readily assembled than has heretofore commonly been the case; themagnet being first secured tol the front plate, then the speed cup putin position and loosely supported in its bearings, after which thesupporting member 24 is` fastened to the foundation plate by the screws25, thus providing a single rigid bearing for the sleeve 33 whichcarries the rotating armature of the instrument.

After the sleeve 33 has been assembled with the bearing 29 the same isheld in place thereupon by the screw 49 thus pro.- viding, asy abovepointed out, an instrument il which a single unusually long and rigidbearing is. provided for the main rotating element of the instrument,and in which all the parts involved in the speed indicating function aresupported from the front supporting plate. The assembling is completedby placing the supporting plate within the open front end of the casingwhich, however, in no way provides a bearing for any rotating element ofthe instrument; and it will be appreciated that the entire speedindicating mechanism may be removed from the casing as a single unitarystructure along with the said plate. The single long bearing for thearmature of the instrument avoids binding at the bearings therefor andprovides for long life thereof; and the general concentric arrangementof the several elements which comprise the instrument insure properalignment of the several parts as the vinstrument is assembled upon themain supporting plate.

After the instrument has been assembled and properly adjusted a sealingplate 50`the peripheral edge ofr which engages an annular grooveprovided in the front plate is sprung into place, thereby closing theopening 15 and covering the front jewel bearing and hair spring; whichcover plate, being preferably put in place while the edges thereof aresprung inward, provide a construction in which-the user of theinstrument cannot readily gain access to the hair spring and otherinternal parts and vary the adjustment of the instrument.

Having thus described and explained my invention, I claim and desire tosecure by Letters Patent:

` 1. In a speedometer of the class described; a suitable hollow easinghaving an opening at its front side-orl end; a supporting plate fac .form located `within said casing and sup-' posite said opening;

secured to said casing and acting to close' said opening; speed'indicating'mechanism located Within said casing and supported solelyand entirely by said supporting plate; and a driving shaft supported bysaid casing and operatively connected with an element of said speedindicating mechanism to drive the same.

2. In a speedometer of the class described, a suitable hollow easinghaving an opening at its front side or end, and a rear Wall opasupporting plate se cured to said casing and acting to close saidopening; a Supporting member located Within said casing and supportedsolely and entirely by said supporting plate; a magnet and an armatureconcentric'ally arranged relative to one another and one 'of which is I,rotatably supported by said supporting member `While the other isfiXedly secured to said supporting plate; an angularly movable speed cupsupported by said supporting plate and operativelyassociated with said"magnet and armature; anda driving shaft supported by said rear Wall andoperatively connected with the rotating member afore- Said to drive thesame.

3. In a speedometer of the class described.

ha' suitable hollow casing having an opening atjitl's ,front side orend, and a rear Wall opposite and substantially plane of said opening; asupporting plate fitting within saidfopening; a hollow supporting membersubstantially cup-shaped in ported solely and entirely by saidsupporting plate; a magnet secured tosaid supporting plate-and locatedwithin said support-- ingmember; an angularly movable speed cup locatedWithin said supporting member and arranged adjacent said magnet andsupported from bearings carried one by said supporting plate and theother by -said supporting member; an armature rotatable -upona bearingcarried by said supporting member and having poles vwhich move adjacentsaid magnet and speed cup; and a driving` shaft supported by said .rearivall and operatively connected with the armature aforesaid to drive thesame.

4. In a speedometer of the class described,

4a-suit-able hollow casing having an opening at its front side or end; asupporting plate carried by! said casing :and acting to 4close saidopening; a hollow substantially cupshaped support-ing member locatedWithin said casing and secured to said supporting plate so as to besupported thereby7 and Whichsupporting member is provided with a bearingdisposed substantially at right angles to said supporting plate; anangularly movable speed cup located Within said supparalle'l with theporting member and supported in bearings one carried by said member andthe other by said plate; a magnet located Within said speedcup andsecured to said plate; a rotat-.

able armature supported solely by said bearing and having poles movingadjacent said speed cup and magnet; and a driving shaft operativelyconnected with said armature to drive the same.

5. In a speedometer of the class described,

a suitable hollow casing having an openj ing at its front side or end,and a rear Wall opposite and substantially parallel with the plane ofsaid opening; al supporting plate fitting Within said Opening; a'hollowsubstantially cup-shaped supporting mcmberlocated within said casing andsezured to said supporting plate so as to be supported .thereby, andwhich supporting member lis provide'dfwith a bearing disposedsubstantially 4 yat right angles to said supporting plate; an angularlymovable speed cup locatedvvithin said supportingimember and supportedinbearings one carried by said member and the other by said plate;a'magnet locate-d within said speed cup and secured to said plate; arotatable armature'supported solely i by said bearing and having'. poles.moving adjacent said speed cup and magnet; and a driving shaftsupported bv said rear wall and-operatively connected nWith saidarmature to drive the same.

' 6.` In a speedometer of the class described,

7. In a speedometer of the class described, 4

a suitable hollow casinghaving a supporting lll) plate .at its frontside or end` and which plate is provided with an opening; a speed cupangulaily rotatable about,v an axis disposed substantially at/iightangles to said supporting plate, and having a radially ex' tendingflange at its open end whichv moves across the opening aforesaid vinsaid plate;- a substantially cup-Shaped supporting member carried vbysaid supportingv plate and enclosing said speed cup andv its flangeaforesaid, and which members vis provided with al bearing substantiallyco-aXial' with the axis of rotation of said speed cup; a magnet securedto said supporting plate and located Within said supporting member; anarmature rotatable upon and supported solely by the bearing aforesaid ofsaid supporting member, and the poles of which armature move adjacentsaid speed cup and magnet; and a driving shaft operatively connectedwith said armature to drive the same.

8. In a speedometer of the class described, a. suitable hollow casinghaving an opening in its front side or end, and a rear Wall oppositevsaid opening; la supporting plate secured to said casing and extendingacross said opening; speed indicating mechanism located Within saidcasing and supported solely and entirely by said supporting plate; and adriving shaft having a non-rotatable external casing fxedly secured tosaid cas-v ing, and a rotatable inner core operatively connected with anelement of said speed indicating mechanism to drive the same.

9. In a speedometer of the class described, a suitable hollow casinghaving an opening in its front side or end, and a. rear Wall oppositesaid opening; a supporting plate secured to said casing and extendingacross said opening; a supporting member located Within said casing andsecured to said supporting plate` and having a bearing a't its free end;a magnet carried by said supporting plate; an angularly rotatable speedcup supported` in bearings carried b v said supporting plate andsupporting member; an armature rotatable upon the bearing aforesaid andsupported solely by said supporting member, and ythe poles of which moveadjacent said speed cup and magnet; and a drivingshaft having anon-rotating external casing ixedly secured to said speedometer casing,and a rotatable inner core operatively connected with said armature todrive the same.

lin testimony whereof I affix my signature.

JOSHUA PATRICK.

